CVE-2026-61511
criticalvBulletin 5.x through 5.7.5 and 6.x through 6.2.1 contains an eval injection vulnerability in the vB5_Template_Runtime::runMaths() method within the template r…
vBulletin 5.x through 5.7.5 and 6.x through 6.2.1 contains an eval injection vulnerability in the vB5_Template_Runtime::runMaths() method within the template runtime that allows unauthenticated remote attackers to execute arbitrary PHP code by supplying crafted input through the pagenav[pagenumber] parameter. Attackers can exploit the insufficiently restrictive regex filter by using phpfuck-style encoding with permitted characters to inject and execute arbitrary PHP code via the unauthenticated ajax/render template route without any authentication.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/45093... disclosure@vulncheck.com
- https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/45094... disclosure@vulncheck.com
- https://karmainsecurity.com/KIS-2026-13 disclosure@vulncheck.com
- https://ssd-disclosure.com/vbulletin-runtime-template-runmaths-preauth-rce/ disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/vbulletin-eval-injection-rce-via-vb5-template-runtime... disclosure@vulncheck.com
- http://seclists.org/fulldisclosure/2026/Aug/29 af854a3a-2127-422b-91ae-364da2661108